What Happens If a Plane Loses an Engine?
Sources: FAA Part 25, ICAO Annex 6 · Updated May 2026
The aircraft keeps flying. Every transport-category airliner is certified under FAA Part 25 (and EASA CS-25) to continue safely after an engine failure at any point in flight — including the most demanding moment, just after V1 on takeoff. A twin-engine jet loses thrust capability but retains certified climb performance on the remaining engine. The crew runs the engine-failure checklist, declares an emergency if appropriate, and diverts to the nearest suitable airport. Long-haul twins are additionally certified under ETOPS (Extended Operations) rules that require a single-engine diversion be possible from any point on the route within 120, 180, 240, or up to 370 minutes flying time. Engine in-flight shutdowns are rare — the certified target is 0.02 or fewer per 1,000 engine-hours for ETOPS engines.
How redundancy is designed in
A transport-category twin-jet is certified to take off, climb, cruise, and land with one engine completely inoperative. FAA Part 25 specifies the required minimum performance at each stage:
- →Takeoff: After V1 (decision speed), the aircraft must accelerate, rotate, lift off, and climb out of the airport with one engine out. Performance is calculated for every takeoff, accounting for weight, temperature, runway length, and obstacles.
- →En route: From cruise altitude, the aircraft drifts down to its single-engine maximum altitude. For modern twins this is typically 18,000–25,000 ft — still well above most weather and terrain.
- →Approach and landing: Certified single-engine go-around and landing performance is part of type approval. The aircraft can land normally on a runway suitable for its weight.
Drift-down — the en-route procedure
When an engine fails at high cruise altitude (say FL370), the remaining engine cannot maintain that altitude at full weight. The aircraft descends along a calculated drift-down path to its one-engine-inoperative ceiling — the altitude at which level flight on one engine is possible. This is built into the flight management computer and into the operator's route planning. Drift-down profiles are checked against terrain along the entire route; over mountainous regions like the Himalayas or the Andes, special escape routes are pre-planned.
ETOPS — extended operations
ETOPS rules govern twin-engine long-haul flights over oceans and remote regions where the nearest airport may be far away. An ETOPS-approved aircraft on an ETOPS-approved route must remain within a defined diversion time of a suitable alternate airport at every point. Common approvals:
- →ETOPS-120: 120 minutes single-engine flight time to a diversion airport
- →ETOPS-180: 180 minutes — covers most transoceanic routes (granted to the US fleet in 1989)
- →ETOPS-240/330/370: Extended approvals for South Pacific, Antarctic-fringe, and ultra-long-haul polar routes
ETOPS certification covers the engine, the airframe, and the operator's procedures together. For the engine, the FAA requires an in-flight shutdown (IFSD) rate of 0.02 or fewer per 1,000 engine-hours for type-design approval up to 180 minutes, and 0.01 or fewer for approval beyond 180 minutes. See full ETOPS / EDTO explainer.
What pilots do when an engine quits
The drill is highly rehearsed in simulator training every six months for line pilots:
- Maintain control — apply rudder to counter asymmetric thrust, pitch for engine-out climb speed.
- Identify the failed engine (instruments, vibration, fire warning if any).
- Run the memory items: secure the engine (fuel cutoff, fire bottle if needed).
- Climb on the remaining engine to a safe altitude clear of terrain.
- Run the checklist: confirm systems, fuel balance, electrical and hydraulic configuration.
- Declare an emergency or precautionary diversion as appropriate; coordinate with ATC.
- Plan and fly to the nearest suitable airport. Land normally on the remaining engine.
Famous engine-loss events
Airbus A320 lost both engines to a bird strike shortly after takeoff from LaGuardia. Captain Sullenberger glided to a successful ditching on the Hudson River; all 155 on board survived. Examined in detail in NTSB report AAR-10/03.
Airbus A380 suffered an uncontained engine failure on departure from Singapore. The crew flew for nearly two hours managing damage before landing back at Changi. All 469 on board uninjured.
A Boeing 767 ran out of fuel at cruise altitude (fuel-quantity miscalculation between metric and imperial units). The crew glided 75 nautical miles and landed at Gimli, Manitoba. All 69 on board survived; aircraft repaired and returned to service.
A Boeing 777 lost thrust on both engines on final approach to Heathrow (ice in fuel system). The crew glided to a landing just short of the runway. All 152 on board survived.
How common is engine failure?
Rare. For modern certified ETOPS engines, the in-flight shutdown rate is on the order of 1 per 100,000 engine-hours — so on a typical twin operating two engines, you can expect roughly one in-flight shutdown per 50,000 flight-hours per aircraft. The vast majority of those shutdowns are precautionary (oil pressure indication, vibration, fuel filter warning) rather than catastrophic mechanical failures. Total engine loss (both engines on a twin) due to mechanical failure is far rarer still — the famous cases above involve external factors (bird strike, fuel exhaustion, fuel system icing), not engine mechanical failure.
Sources
- FAA 14 CFR Part 25 — Airworthiness Standards: Transport Category Airplanes
- FAA 14 CFR Part 25 Appendix K — Extended Operations (ETOPS)
- ICAO Annex 6 Part I — Operation of Aircraft: International Commercial Air Transport
- ICAO Doc 10085 — Manual on Extended Diversion Time Operations (EDTO)
- FAA Advisory Circular 120-42B — Extended Operations
- NTSB Accident Reports — US Airways 1549, Air Canada 143, BA 38, Qantas 32